Process for the production of artificial stones



Patented May r, was

ronamv :tnxon, or snnnncflzunren, swrrznnnann; nssrenonro ALBERT 'r. o'r'ro & sons, me, or new roan, N. 32., aconronn'rxon on NEW roan rnocnss son was rnonucrronor ARTIFICIAL s'ronns Ito Drawing. Application filed November 2; 1925, Serial m). 66,395, and in Germany December 2%, 1924;

The present invention relates to a new andimproved process for the production of artificial stones by fusing the components.

The new process consists in that 'silicic acid 5 or compounds of silicic acid are'fused with such inorganic salts disassociating in the heat and being easily decomposed by the former, the acid radical escaping as a gas.

Preferably such salts are made use of which 310 facilitate the fusing process such as given by way of examples'hereinafter.

Forsterite is pure magnesium olivine and in composition corresponds to the formula Mg SiO -Great difficulty is encountered in the technical manufacture of this compound as its melting point is situated in the neighhour-hood of 1890 Serpentine and mag nesia are used as the initial materials according to the following equation 'Si U Mg H +MgO=2Mg SiO +QH O which gives. quantitative yield of forsterite on melting the corresponding mixture. The

disadvantages of this method are first, that serpentine has a high melting pointor only.

becomes liquid at high temperatures, and secphate are intimately mixed with 1 kg. of

0nd that magnesia sublimesand therefore escapes at relatively low temperatures (far below its melting point) 80 These difi'iculties can be overcome if care is taken to obtain a'thin liquid melt which is already reactive at relatively low temperatures (10001500); in this way the magnesium oxide is retained in the melt. This result is achieved according to this invention by using a sulphate of the metal concerned. Divalent or trivalent metals are employed and the method is applicable not only to the production of mono-ortho silicates but to any silicates which are more basic than an equimolecular mixture of the mono-ortho-s1l1cate the following manner. Dehydrated. MgSO is taken as initial material instead of MgO or MgCO and previously powdered quartz sand instead of serpentine. Magnesium sul- V phate forms a mixtureof relatively low melting point with powdered quartz sand, the

melting point of the melt rising continuously up to the melting point'of Mg SiCL; by-

contlnuous evolution of S0 or -(SO" The reaction is as follows:

Example 1. 4 kg. of .dehydrated magnesium sulpowdered quartz sand and melted together, forsterite being formed accordingto the equation j q 'QIl/IgSU; SiO Mg SiO QSOe 2. 4 kg. of ground serpentine are mixed with 1.730 kg. of dehydrated magnesium sulphate and melted, forsterite being formed according to the equation:

3. Processes 1 and 2 maybe combined.

4. 4.- kg. of ground serpentine are mixed .with 1215 kg. magnesiumnarbonate and 2 kg. ammonium sulphate and melted together.

Forsterite is formed according to the equation; 1 4

Sii 9 g3 4+ Mg Oa 2SO4I= Basic sulphates or-.basic sulphates mixed with oxides of metals can also be used prQ-;

which'will give to I vided that the thin liquid'melt isobtained.

In a similar manner artificial diopside may be produced. Diopside is a ,magnesiumcalcium-silicate and in its stochiometric comosition corresponds to gCa(SiO{ SiO Pure diopside has a melting point of 1391 C. it may be produced by fusing calcium carbonate, magnesium cari bonate and quartz according to the equation The same product may be obtained by fusing dolomite and quartz.

Artificial stones produced in the manner described, have the properties of diopside, they resist acids andv alkaline solutions, as Well as mechanical tension and pressure.

' It will be understood that the fused mass will be permitted to cool in a suitable mould the artificial stone the desired shape and size.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. The process of producing an artificial forsterite which includes the step of fusing a mixture of serpentine and magnesium sulphate, the acid radical of the sulphate escaping as a gas.

2.The process of producin an artificial .forsterite including the steps 0 fusing a mixture of quartz and magnesium sulphate,adding to the fused mass equivalent parts of serpentine and magnesium sulphate, and further heating the added materials to efiect their fusion.

3. The process of forming an artificial stone. which includes the step of fusinga material rich'insilicic acid and an inorganic salt having an alkali earth metal base and an acid radical which separates and passes off as a gas during the fusing. y

In witness whereof I afiix my signature.

J OHANN J AKOB.

the formula 

